The fossil record indicates that the very first foraminifera
(with a hard shell) was the unilocular simple agglutinated Allogromiina, which
evolved into the calcareous agglutinated Textulariina during the Cambrian. While the Textualariina were a dominant group early in the Paleozoic, the Fusulinina became dominant later in the Paleozoic
(from the Silurian).The Fusulinina are morphologically larger with compound, microgranular walls and complex internal structure and they constitute much of the Late Paleozoic shallow-marine
limestone seen today (BouDagher-Fadel, 2008).

Because of their importance, the main focus of this sub-page is the suborder Fusulinina. Other suborders we will discuss here are the Lagenina, which evolved in the Silurian, the Miliolina and the early
Involutinina. The lagenines, miliolines and involutinines were morphologically
small and primitive throughout the Paleozoic, measuring between 0.4 and 1.3 mm in diameter. The evolution of the Paleozoic larger foraminifera is shown to the left (BouDagher-Fadel, 2008).

The suborder Fusulinina contains twelve superfamilies and 418 distinct genera (Loeblich and Tappan, 1988), most of which became highly specialized during the latter part of the Paleozoic. Rapid evolution facilitated large and diverse lineages of Fusulinina and they achieved a remarkable size for a single celled organism. By the end of the Permian, some forms of fusuline reached 15 cm in diameter (BouDagher-Fadel, 2008). Despite their dominating presence, complicated structure and large size, they were extinct by the end of the Paleozoic.

Below we present a brief description of each superfamily and family and include a description of select genera beneath each family. For more detailed taxonomic descriptions of all genera, see Loeblich and Tappan (1988) and Rauser-Chernousova et al. (1996). Additionally, please refer to the paper by M. BouDagher-Fadel (2008), from which this page is summarized, and references found there-in, especially regarding the individual descriptions for each family. Also, refer to the Miracle home-page, constructed by Dr. Marcelle K. BouDagher-Fadel of the University College of London (University College of London - MIRACLE).

For a list of key Suborders, Superfamilies and Families that are discussed in the following sections, please see the diagram below (after BouDagher-Fadel, 2008). This diagram, as well as the large diagrams in the following section can be viewed at a larger scale once the shadowbox has been activated by right-clicking on the diagram and opening it in a new tab (Google Chrome) or selecting the View Image function (IE).

SUBORDER FUSULININA

Test: homogeneously microgranular primary test made of low-magnesium calcite, in which the crystal units have no optical alignment.

The Nodosinelloidea evolved from the Parathuramminoidea via the free Moravamminoidea. This evolution of the families is shown graphically below. Please refer to Figure 1 (below) to trace the evolution of the specific family and their genera.

Test: Free with more than one distinct chamber, partially septate or fully septate

The Tournayellidae are divided into two lineages, which evolved in the Devonian and followed parallel lines of evolution. the first lineage consists of simple planispiral, non-septate forms with an initial proloculus and an aperture at the end of an uncoiled tube. These forms developed a compound wall and rudimentary septa in the Late tournaisian to almost complete septa in the Late Visian. the second lineage is made of streptospiral tubular forms which gradually developed rudimentary septa also in the late Tournaisian, Please see the diagram below which describes the evolution of the Tournayellidae (BouDagher-Fadel, 2008).

Schematic evolution of the Tournayellidae

Family Palaeospiroplectamminidae

Test: initially streptospiral then planispiral and in later stages becomes biserial

Geologic range: Late Devonian to Carboniferous

Superfamily ENDOTHYROIDEA

Test: streptospiral with many chambers followed by a rectilinear stage in some forms

Wall: microgranular and calcareous, but some forms evolved two to three distinct layers

Geologic range: Late Devonian to Triassic

Family Endothyridae

Test: small, multilocular, enrolled with evolute lanispiral coiling with well developed septa in early whorls or initially streptospiral to planispiral characterized by the development of secondary deposits of cacite on the chamber floor

Aperture: low equatorial, advance forms may become uniserial with a cribrate terminal aperture

Test: large, varies from spherical to fusiform; the development of seondary deposits of calcite is prominent in most forms but the numerous chambers are subdivided by folds or septula

Geologic range: Middle Devonian to Permian

There are over 100 genera recognize belonging to this superfamily. The Fusulinoidea have special morphological diagnostic characteristics that make this family unique. There are five types of wall structures that characterize the Fusulinoidea. The first four types of wall characterize the Ozawainellidae, Staffellidae and the Fusulinida. The last type of wall belong to the Schwagerinidae and Verbeekinidae. Please refer to the figure and legend below:

Form B: Three-layered walls, the late and early tectorium surrounding the dark layer of the tectum

Form C: Four-layered walls, wth the late and early tectorium surrounding the tectum and a glossy layer called the diaphanotheca

Form D: Three-layered walls, where the late tecctorium disappears and they are left with the tecturm, diaphoanotheca and the early tectroium

Form E: Composed of a tectum and a glossy layer with alveoles running through it

Five types of wall structure recognized in the Fusulinoidea

Key recognizable features of the Fusulinoidea

The Fusulinoidea was divided into eight families, based on wall structure, presence or absence of the chomata and the degree of septal folding in the test. As stated, there are over 100 genera identified. Please refer to the works of BouDagher-Fadel (2008), Loeblich and Tappan (1964; 1988), Haynes (1981) and references therein for descriptions of these important families, subfamilies and genera belonging to the Fusulinoidea.

Family Loeblichiidae

Family Ozawainellidae

Family Schubertellidae

Family Fusulinidae

Family Schwagerinidae

Family Staffellidae

Family Verbeekinidae

Family Neoshwagerinidae

Schematic diagram of the most advanced forms of fusulines

SUBORDER LAGENINA

Test: Members of this suborder have walls that are monolamellar, with or without secondary laminations, with radiating calcite crystals which have the crystallographic c-axis perpendicular to the surface.

Wall: Only advanced forms have secondary lamination. Reiss proposed an extensive reclassification of lamellar forms and Gronlund and Hansen (1976) proposed new terminology for lamellarity;

atelo-monolamellar- primitive lagenines, no secondary lamellarity

plesio-monolamellar- secondary lamellarity envolops some but not all chambers

Test: This family includes the uniserial Lagenina with atelo-monolamellar or plesio-monolamellar wall structure consisting of radial-fibrous

Geologic range: Late Carboniferous to Late Permian

Genera: Protonodosaria. Elongate test with horizontal straight sutures and round aperture. Late Carboniferous to Late Permian.

Family Ichtyolariidae

Test: elongate uniserial with a single-layered wall. May show secondary lamination.

Aperture: simple, terminal

Geologic range: Early Permian to Early Cretaceous

Family Robuloididae

Test: uniserial, enrolled

Wall: atelo-monolamellar

Aperture: terminal

Geologic range: Late Permian

Genera: Calvezina. Proloculous followed by five or more uniserial chambers, weakly trochospirally enrolled.The chamber is slightly compressed laterally and size increases from hemispherical to lobate. Late Permian.

SUBORDER INVOLUTININA

This suborder includes all forms with an enrolled second chamber. Walls are aragonitic but commonly recrystallized to give a homogeneous microgranular structure. They have an umbilical region with pillar-like structures on one or both sides of the test and range from Early Permian to Late Cretaceous.

Superfamily INVOLUTINOIDEA

This superfamily comprises forms consising of a proloculus followed by a planispiral to trochospiral enrolled trubular second chamber. Early Permian to Late Cretaceous. This superfamily is discussed in more detail in the following section on Triassic forams.

SUBORDER MILIOLINA

Test: porcellaneous and imperforate, which are made of high-magnesium calcite with fine randomly oriented crystals

Geologic range: Carboniferous to Holocene

Superfamily CORNUSPIROIDEA

Test: free or attached and composed of a globular proloculus followed by a tubular enrolled chamber. The coiling is planispiral or trochospiral, evolute or involute.